In medicine, extensive use of instrumentation is made to obtain images in the diagnosis of diseases.
In particular, both the ultrasound images and the scintigraphic one are used for the secondary diagnosis of those cases for which disease is suspected after previous radiographic examinations.
Recently, several reports have demonstrated the greater diagnostic predictivity of dual “imaging” systems, or detectors capable of providing a double image of the object under examination.
The basic criterion is to combine two complementary images: a morphological image that can provide anatomical details (RX, CT and NMR) with another capable of providing information on the biological functionality (imaging obtained with the use of molecules labeled with radionuclides, termed radio-tracers, such as PET SPECT).
The solution most proposed in the known art is represented by large and expensive systems based on the use of a tomographic ring wherein the two detectors are integrated, such as SPECT CT, PET CT, CT NMR and recently PET NMR.
These systems known in technology have the disadvantage of being very bulky and very expensive, so as to remain the exclusive prerogative of large industrial groups such as General Electric, Siemens, Philips and Toshiba, which can make products similar to each other, with minor differences.
In addition to the mentioned morphological imaging techniques, the use of ultrasound images for diagnosis is widespread in medicine; the main advantages of ultrasound techniques are represented by their ease of use without dosimetric requirements (in contrast to the scintigraphic ones, wherein it is necessary to use sources with X-rays) and by the excellent level of the obtainable images, usually obtained in a few seconds at resolutions lower than a millimeter, as well as with lowest cost per single application. In contrast, a disadvantage is represented by the fact that the detection of the images must be performed by very experienced staff, with obvious repercussions on the operating costs of existing equipments. Moreover, current ultrasound detectors have the further disadvantage of being not able to be integrated in a tomographic ring.
Among said ultrasound applications, in particular, the radio-guided intraoperative applications are here mentioned, which are based precisely on the use of ultrasound probes in oncological surgery, wherein experiencing a probe capable of working in echo-mode scintigraphic could be highly interesting.
In the prior art, in said field of cancer surgery, to date, to the knowledge of the Inventors, substantially one application solution comes out to be realized, which attempted to propose the use of ultrasound probes in dual imaging systems in medicine, but has the obvious disadvantages of being constructively very complex and, therefore, also very expensive.
It has been realized at the University of Berkley, Calif. USA, and proposes the realization of a detector echo-PET for imaging the prostate, where a complex and expensive system of laser pointers is used for sighting at each instant the position of the ultrasound probe and try to contextualize the scintigraphic image with the one coming from positron tomography (PET) [J S Huber et al., “Dual-Modality PET/Ultrasound Imaging of the Prostate”, 2005 IEEE Nuclear Science Symposium Conference Record].
Recently a third solution has also been reported which involves the construction of a detector of ECHO SPECT type, i.e. provided with a pair of detectors, a first ultrasound one and a second scintigraphic one, which have however the disadvantage to be completely independent during the phase of echo-scintigraphic analysis and, therefore, require specific skills by the user of the detector.
Concerning the simultaneous detection of signals from gamma radiation and acoustic signals, US2012/032086 A1 describes a portable scanning probe for intraoperative use. The probe is an X-ray scanner integrated with a series of solid state photomultipliers. The device also comprises a location tracker able to acquire the position of the probe itself. While the probe is moved on the surface of the patient to be analyzed, the optical sensor acquires images of the field and a software superposes them onto the nuclear images to form a composite image. Although this probe has been proven with a ultrasound guide, the patent document does not specify the integration of the ultrasonic probe with the X-rays one, but only the use of two techniques per se as separated, the embedded images being by the way only the optical and nuclear ones.
US2009/030310 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. However, it is specified (par. [0013]) that the scintillator is formed of a single crystal, and that this does not allow to realize a real three-dimensional tomography. This however is made by reconstruction using a traditional PET detector which is far from the probe.
A U.S. Pat. No. 4,995,396 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. The two detectors are placed side by side or juxtaposed. The two devices collect the signals by an angular scanning, obtaining at the end an angular distribution of the count and echo signals. The imaging definition is linked to the plurality of simultaneous acquisition of a number of viewing angles whose selectivity in angle defines the spatial resolution of the system. It deals with an endoscopic probe in which the device has echo imaging functions, not of B-mode type, while the detector array has only a function of measuring the intensity of gamma radiation collected in a wide viewing angle and that does not offer any chance to process the signal intensity in order to make a spatial image of the radiation source. From FIGS. 3, 11, 35 and 40a can be deduced that the two detectors operating at 180 degrees and the collimator is used in order to limit the angle. In fact in 11, 35, 40a indicators of intensity of measured gamma radiation are shown and in no other figure neither the use of images gamma nor consequently fusions between images of two different modes are shown. The display of images is made so that the echo picture appears together with a bar graph of the intensity of gamma radiation. The gamma image is then not visualized, but a LED indicator divided into colored bars is used: the greater the number of illuminated indicator bars, the greater the intensity of the gamma radiation.
US2008/230705 A1 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. However, the scanning direction of the two sensors is substantially orthogonal, and a tracking device for detecting the position of the probe is provided. Based on the data of the tracking device, the images of the scintillator are contextualized. Nothing is said however on the integration of ultrasound images.
U.S. Pat. No. 6,212,423 B1 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. However, the scanning direction of the two sensors is not coincident, as specified in col. 7 I.22-27, and this poses problems in the superposition of the images obtained by the two sensors.
WO2004/042546 A1 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. The endoscopic probe is provided with a tracking device for detecting the position of the probe. The direction of the two detectors is equal in the sense that the two detectors are placed side by side and are parallel, the field of view is not, however superimposed. Consequently, the system makes use of fiducial markers to align the images. Document WO2004/042546 A1 provides a protocol substantially rather than a device to optimize the comparison and the fusion of anatomical images with functional images, regardless of the techniques by which they are acquired.
EP 2347791 A1 describes an endoscopic probe which contains in the head both a scintillator and an ultrasound sensor. However, the scanning direction of the two sensors is not coincident, and this poses problems in the superposition of the images obtained by the two sensors.
Article of Pani et al. “Dual-Modality Ultrasound Detector SPET for Molecular Imaging”, Nuclear Physics B. Proceedings Supplement, vol. 215, no. 1, 1 Jun. 2011, pp. 319-323, describes an integrated probe. The gamma counting rate in this probe is not beneficial and the recording of images is difficult.